原标题：Maxim MAX14870 4.5-36V DC有刷马达驱动方案

　　Maxim公司的MAX14870/MAX14872是业界最小的4.5-36V DC有刷马达驱动器/继电器驱动器,非常低的开态电阻降低了驱动器的功耗,主要用在打印机和扫描仪,继电器驱动器和销售机与游戏机.本文介绍了MAX14870优势和特性,功能框图,以及MAX14870评估板主要特性,框图,电路图,材料清单和PCB设计图.

　　The MAX14870/MAX14872 motor drivers provide a small, low-power and simple solution for driving and controlling brushed DC motors and relays with voltages between 4.5V and 36V. Very low driver on-resistance reduces power dissipation.

　　These drivers feature a charge-pump-less design for reduced external components and low supply current. Integrated fast-decay current regulation allows user-adjustable peak startup motor currents and requires mini­mal external components.

　　A separate voltage-sense input (SNS) reduces current sensing errors due to parasitic trace resistance.

　　The MAX14870/MAX14872 features shoot-through protec­tion and internal free-wheeling diodes that absorb inductive motor currents. Driver outputs are short-circuit-protected from shorts to ground, to the supply, and between M1 and M2. An active-low FAULT output signals thermal overload and overcurrents during fault conditions.

　　The MAX14870 has PWM and direction-control inputs, while the MAX14872 has forward and reverse inputs for direction control. See the Function Tables.

　　The MAX14870/MAX14872 are available in a 12-pin (3mm x 3mm) TDFN-EP package and operate over the -40℃ to +85℃ temperature range.

　　MAX14870优势和特性:

　　Small Package Handles High Power and Reduces Footprint Circuit Size Up to 2.5A Peak Motor Current

　　Space-Saving TDFN-EP (3mm x 3mm) Package

　　Flexible 4.5V–36V Supply Enables Longer Runtime on Batteries

　　Low Power Consumption Runs Cooler and Longer 280mW (typ) Total Bridge On-Resistance

　　1mA (typ) Supply Current at 30kHz/24V

　　10μA (max) Standby Current at 12V

　　Simplified Designs Reduces Time to Market Charge-Pump-Less Architecture

　　Current Regulation Only Requires a Sense Resistor

　　Current-Sense Input Simplifies PCB Layout

　　Integrated Protection Provides Robust Driving Solution Short-Circuit-Protected Drivers

　　Thermal-Shutdown Undervoltage Lockout

　　Diagnostic FAULT Output

　　-40℃ to +85℃ Temperature Range

　　MAX14870应用:

　　Printers and Scanners

　　Relay Drivers

　　Vending and Gaming Machines

　　图1.MAX14870功能框图

　　图2.MAX14870/72功能框图

　　图3.MAX14870/72典型应用电路

　　MAX14870评估板

　　The MAX14870 evaluation kit (EV kit) consists of aMAX14870 evaluation board and software. The EV kit is afully assembled and tested circuit board that evaluates the

　　MAX14870 full-bridge DC motor driver.

　　The EV Kit may also be used to evaluate the MAX14872.

　　The EV kit is designed to work with a PC-based GUI or asa standalone board, demonstrating all the major featuresof the device. The EV kit includes Windows®-compatiblesoftware that provides a graphical user interface (GUI)for exercising the features of the MAX14870. The EV kitis connected to a PC through a USB A-to-micro B cable.

　　MAX14870评估板主要特性:

　　●● Operates from a Wide 4.5V to 36V Supply

　　●● Standalone or Software-Controlled Operation

　　●● USB-PC Connection

　　●● Proven PCB Layout

　　●● Fully Assembled and Tested

　　图4.MAX14870评估板框图

　　图5.MAX14870评估板电路图(1)

　　图6.MAX14870评估板电路图(2)

　　MAX14870评估板材料清单(BOM):